This invention is directed to an earth working apparatus designed specifically for conditioning of dirt tracks for use in horse racing. Such race tracks require periodic surface conditioning to form a loose and uncompacted surface layer for protection of the hoofs of the horses and improve the racing. As a consequence of track use and environmental weather conditions, earth tracks will frequently have the soil particles compacted into a solid mass that is damaging to the hoofs of horses and does not provide a suitable track surface that produces adequate traction for either optimun performance or safety.
When an earthen track has its surface severely compacted, it forms an extremely hard and substantially smooth surface that becomes exceptionally slippery with respect to a horses' hoofs which are provided with iron shoes. During the course of utilization of such tracks, the compacting of the soil is compounded by the weight of the horses and pounding of the hoofs in effecting further compaction of that soil. Such a hard compacted surface results in injury to the horses through the increased shock forces occasioned as a consequence of running and this eventually results in physical injury and damage which may be of a prolonged and often permanent nature to the hoof structure, bones, muscles, and cartlidges so as to prematurely render a horse physically unfit for further racing. Additionally, a hard, compacted track surface provides little in the way of traction and the horses' hoofs will readily slip and thereby detract from their race performance. Furthermore, the hard smooth surface condition may enhance the likelihood of injury in that the horses may slip and fall.
Different types of races require different depths of soil conditioning. For some races, it is desired that the soil have a very shallow conditioned surface layer, such as being of the order of one-half inch. Other race conditions require that the surface be conditioned to a depth of two to three inches. It is also desired that the track surface be level and have a uniformly prepared surface so as to provide a standard track condition for all horses in a given race. This uniform condition as to degree of compaction or depth of the relatively uncompacted surface layer is difficult to achieve and maintain as each race tends to cause shifting of the track surface to an extent that high and low areas are developed around the track as well as continually compacting the track surface. This unevenness may be more predominant in certain areas, such as on turns, but it nevertheless occurs throughout the complete extent of the track.
Various types of apparatus have heretofore been utilized in the conditioning and preparing of dirt tracks for horse races. One common type of apparatus employs a rigid frame structure on which are mounted a large number of rod-like tines or teeth. This apparatus, with those teeth vertically oriented, is pulled over the track surface with the objective of the teeth being to penetrate in the upper surface layer of the track and dig into the earth so as to loosen it and form a top surface layer of relatively loose and uncompacted particles. While the known prior apparatus provided with tines is capable of performing this general function of loosening the earth, the prior apparatus has not been found to be capable of forming a carefully controlled surface layer.
It is known that attempts have been made to construct machines that were specifically designed to perform the track conditioning function. One such machine comprised a rigid structural frame mounted on wheeled supports in fixed relationship so that the frame was carried at a fixed elevation with respect to the track surface. A plurality of earth working tines were provided and were mounted on several support beams carried by the structural frame. These beams were mounted on the frame for selective positioning in a vertical direction to obtain a desired tine penetration depth in the track surface with each beam being independently adjustable. While being capable of performing an earth working function so as to condition a track surface, such prior machines have not been found completely satisfactory. One major problem is the difficulty encountered in attempting to alter the depth of penetration of the tines into the underlying track surface. It is a time consuming task to separately adjust the vertical position of each beam on the frame and, with such independent adjustment, it is extremely difficult to obtain the desired uniformity of working depth. Another significant problem with the prior machines is their relative inability to achieve sufficient structural strength through adjustable mounting of the tine support beams on a frame to enable the machine to withstand the forces usually encountered in conditioning of race tracks.